A common injury, especially among athletes and people of advancing age, is the complete or partial detachment of tendons, ligaments, or other soft tissues from bone. Tissue detachment may occur during a fall, by overexertion, or for a variety of other reasons. Surgical intervention is often needed, particularly when tissue is completely detached from its associated bone. While a variety of different techniques and devices can be used for ligament or tendon attachment, filament or suture, also referred to herein as a joining element, is often used to help secure the ligament or tendon to bone.
Despite the fact that the joining element has been used in connection with ligament and tendon repairs for quite some time, there is still a risk of failure resulting from the joining element coming loose, for instance due to load application. Loads that are exerted on the joining element between bone and tendon are very different. Over long periods of time it can be desirable for the joining element to contract such that the joining element tensions between the bone and tendon. Meanwhile, movements on the part of the patient may subject the joining element to rapidly increasing high loads, under which the connection can sometimes fail.
Some embodiments of joining elements include a more solid outer sleeve with a flexible, extrudable core disposed within at least a portion of the outer sleeve. Knots can be formed on either or both ends of the outer sleeve, for instance by forming a knot in the flexible, extrudable core, and the core can extend distally beyond the knots, and thus distally beyond the terminal ends of the outer sleeve. Over time, the joining element can be hydrated by fluids in the body. This can cause a length of the outer sleeve to shrink, while the flexible core can actually expand in length due to the core being configured to absorb fluid. For example, the core can include silicone and salt, and the salt can help absorb fluid surrounding the joining element, in turn causing terminal ends of the core to grow further away from the knots at the distal ends of the outer sleeve. A person skilled in the art may find it beneficial to limit the amount of silicone that extends from the knots at the distal ends of the outer sleeve.
Accordingly, there is a need for devices, systems, and methods to reduce the amount of flexible material disposed distally beyond a knot associated with a joining element having an extrudable core.